I know just how much this reveals my clueless caravanner stature, but I posted the thought below in another thread a day or so ago and the more I've thought about it, the more I've scratched my head ... So tell me what I've got wrong :-)
Damp meters - do dealers/private sellers really let you ram them into the woodwork, willy nilly (I'm not too sure what they look like yet, though I plan to find out ASAP, but I figure they're electronic gadgets with the spike on the end?!)? Surely it's not good for the appearance of the caravan to be tested by every prospective buyer over their lifetime?!!!!
I thought the same a little while ago when I read a similar thread. I don't think I would have let anyone stick holes in my caravan walls
I believe damp meters have two prongs which connect the circuit if damp is present. I don't think they have to be pushed right into the walls to get reading. If you have ever had a survey done on a house it is the same thing. The contacts are just placed on the wall...which then prompts the question, 'What if the outside is dry but the core is wet?'
Quote: Originally posted by Bob61 on 24/4/2011
...which then prompts the question, 'What if the outside is dry but the core is wet?' ....
Exactly! So the best thing is to file/sand the probe points down to very fine, sharp points, so that you can pierce the surface but without leaving large holes....
You definitely need to get under the surface to tell whether there is any damp in or under the surface....
Gram
------------- What's the difference between a chicken?
I actually have bought one of these gadgets for peace of mind testing, and yes you do have to pierce through the vinyl wall covering and into the boarding below to get an acurate reading, otherwise you would just be picking up the readings of any surface moisture. But, most people who own these gadgets file down their prongs or solder on sewing needles to the existing prongs so that any holes made are so tiny that they are virtually undetectable to the naked eye.
My Caravan has been tested over by 2 dealers plus a couple of times ourselves, yet you cannot tell by looking at it that its ever been done at all, no visible pin-pricks anywhere.
I bought my test meter online from a company called Indigo Starfish for £16.99, after returning the first one which was made by Stanley to B&Q, which dispite its £40+ price tag, was useless and gave false readings of zero when we tested it in a piece of rotten fence post out of our garden, so it was swiftly returned for a refund.
Julia
------------- Just love to be out amoungst Nature and Wildlife
Celebrating 37 years of Caravanning in 2019, Recently Considered Retiring, but Totally Addicted for Life!
Thank you all! Well I've just been off and had a search for damp meters, and yes, they do look a bit vicious ... It feels like even trying to use them in inconspicuous corners would look like the caravan had been subject to the attack of the vampire bats! I don't mind so much in a dealership as I assume they're expecting it, but I figure a private seller might get quite seriously miffed ...
There seems to be various thoughts on which ones are best - but have discovered that for about 20 quid for a weekend HSS hire the one that's really flippin expensive but generally considered excellent. Think
This is the one i use Click_here , it's expensive , but the probes are extremely sharp and you'd have a very hard job spotting where the wall had been tested .
Thanks Wizard - I reckon that's the same one as is on hire from HSS here http://www.hss.com/g/49420/Damp-Meter.html? Have you filed down your probes or were they always so sharp?
I have the Protimeter model the same as Wizard's. This it the model commonly used by caravan workshops. I used to hire one from a local hire shop.
However after loosing a lot of money on a damp caravan, and then having damp discovered on a relatively new 'van, I decided that it was worth getting my own so that I could check my 'van regularly.
I try to use the prongs in places where the pin pricks are not too obvious and they do not really show. I have NOT sharpened the prongs on my meter as they were already very sharp.
Hi, I used to use these when I was in a former job. They give a reading at WMC, Wood moisture content reading. In the internal adhesed cladding trade, 14-16%WMC is considered to be the wettest a substraight can be if you want to work on it. Anything beyond that would not allow adhesives to work etc.
I was listening to a maintenance engineer recently explain to a customer, that he had a reading of 26% in one corner of the van, and that this wasn't anything to worry about, as they would no take any action unless the reading came back at above 30%. I was really suprised to hear this, as in the building trade, 26% is considered still pretty high, too high for most adhesives to work etc.
26% is what I would describe as damp, 30=60 wet, 60-90+ringing wet through.
Worth also noting that even new protometers can vary a little in the reading you get back from them.
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Topic: Using a damp meter
